There are many spray gun type applicators known in the art of lawn and garden chemical application. Typical hose end lawn or garden sprayers are aspirator units which apply fertilizers, pesticides or other chemicals at a fixed, low dilution ratio. To utilize concentrates which must be diluted to high ratios, the user normally predilutes the concentrate with water. This is accomplished by volume measurement of the concentrate with a spoon, cap or other measuring device into a sprayer mix jar. Water is then added to obtain the proper premix concentration. The prediluted concentrate is then further diluted to its final dilution ratio as the sprayer is operated.
Such predilution procedures require the manual handling of concentrated chemicals with its attendant risks. Moreover, the user must generally purchase the concentrate in larger quantities than are necessary for a single application and thus containers of the concentrated chemical must be stored for extended periods after they have been opened. On the other hand devices which attempt to avoid predilution by diluting the concentrate at a high ratio in one (1) step are not satisfactory because of very poor accuracy. The concept of two-step mixing or dilution of chemicals, including such use in spraying devices is known. See, for example, U.S. Pat. Nos. 2,006,437; 2,599,678; 2,711,928; 2,760,820; 3,104,823; 3,181,797; 3,499,606; and 4,027,822. However, the devices shown in these patents are either cumbersome or otherwise unsuitable for garden spray devices.
U.S. Pat. No. 3,165,114 issued to Garret discloses a dispensing package of fluid soluble material capable of use with a standard feed mixer device. Some of the flowing water is diverted down through a nipple and inlet tube into the bottom of the package. Suction draws the dissolved material through an outlet tube. The device requires water to constantly flow through it, and does not provide a barrel valve which could shut off or control the flow.
U.S. Pat. No. 3,198,438 issued to Hultgren, et al. requires a trigger action to push a tapered plug out of an aperture, allowing water to flow into a mixing chamber to create a venturi suction to draw fluid out of a collapsible container. The device will not permit the use of a solid chemical, and does not have applicant's inventive use of a rotatable barrel valve to dilute a chemical or to control the discharge of the diluted solution into the environment. U.S. Pat. No. 3,255,972, also issued to Hultgren, et al. discloses a disposable container for use with sprayers of the type disclosed in the '438 patent.
U.S. Pat. No. 3,554,450, issued to D'Muhala teaches a spray gun which accommodates removable cartridges containing various solids or liquids. An end cap is unscrewed to control water through a mixing chamber and out a nozzle. The device does not provide for re-usable cartridges, as each cartridge must be pierced to permit mixing with the water flow. There is no means to partially dilute a chemical, or to convert a solid chemical to a fluid prior to expulsion through the nozzle.
U.S. Pat. No. 3,915,191 discloses a water mixing device for a shower which may be fitted to the taps of a bath. A selector valve selectively permits water from an inlet chamber to flow through various enclosures of a second chamber. At least one (1) enclosure has a container to receive a soluble substance such as soap. No initial dissolution of the soap is provided for, and the soap is transported by direct flow of the water, and not drawn by aspiration.
U.S. Pat. No. 4,491,254 issued to Viets, et al. teaches an applicator for dispensing a chemical in dilute aqueous form. The applicator has two (2) containers. The second container receives a chemical which has been diluted with water from the first container. A two-position, rotatable valve directs the flow of water into either the first container to predilute a chemical, or to flow across an aspirator to mix with the prediluted chemical and discharge it through the exit end of a passageway. Viets' device requires removing caps from the containers to add chemicals, and to thread the containers together to attach them, a cumbersome and potentially dangerous procedure. The valve taught by Viets, et al. only has two (2) positions. Water is constantly flowing either into the second container to dilute a chemical or through the passageway. An operator must use a conventional nozzle, which must be specially adapted to attach to the applicator to turn the water on or off to control the flow.
U.S. patent application No. 595,523 (inventor--Styne and assigned to Applicant's assignee) has been granted an allowance by the U.S. Patent and Trademark Office, but has not yet issued at the time of filing this patent application. The patent that shall issue from U.S. Ser. No. 595,523 is hereby incorporated by reference for all purposes. Styne teaches a spraying apparatus having a sprayer head and a cartridge. A barrel valve controls whether an entering fluid flows directly into a mixing chamber, or flows through a tube into the cartridge, or does not flow at all. A membrane is required at the top of the cartridge, and is punctured by sprayer head tubes during attachment. Styne does not teach a device that ensures against leaks, that has a self-sealing, spill proof cartridge, or that permits an easy flow-control means.
The prior work is limited in the attempts to easily, economically, safely, and environmentally soundly provide a device to dilute and dispense various insecticides, herbicides, cleaners, and fertilizers. There is therefore a need for a spraying device that provides an operator with immediate flow control, and an interchangeable and reusable cartridge that is quick and easy to attach to a sprayer head, that minimizes leaks, and is safe to use.